AMP Seeks More PJM Scrutiny of TO Projects | 25 Amp Circuit Breaker

Point is, there are already pretty well established and widely accepted methods for uniform heating. Why re-invent the wheel AND sacrifice safety?

Of course in this case, there’s less heat per length of track, but the tracks are longer. So it cancels itself out in the end.

Your advice / admonition overlooks the reasonable likelihood that the part wasn’t *really* rated for what it *claimed* to be rated for, nor was it constructed in a manner to keep it safe in the event of an actual failure– as in the article’s example. Such that even if he were a licensed and well-experienced “electrician” (or anything else), it STILL would (could) have failed and caused the same problem. So what you’re saying IS good advice in a general way, but only partially relevant to the actual incident from the article, IMO of course!

The first was when I was a wee, messing w/ a big 24v motor w/ weight (read: kickback voltage as it spools down && lots of amperage) and I turned it on w/ my hands on both leads…

I forgot to say that 220 volt AC is effectively 310 volts peak, so therefor one could instead use 300 volts DC instead, giving roughly 25% less current to carry in the wires to get the same power in the end.

Continuing USWaterRockets: PCB could just have the solder mask on, mostly for oxidation/contamination protection, with the heating element trace a single top layer. Put a plate of borosilicate glass (maybe tempered?) tightly over it to spread heat and protect from shock, with overhang on the hazard side. If you want to get fancy, add an “active” indicator LED and a few thermal sensors on the bottom layer. Mind your PCB glass mat material and construction – make sure that the construction can handle the heat (a good [not great, not cheap] construction can handle ~170C before it reaches glass transition temperature)

Creating a PCB heat bed isn’t an art – it’s a science. There are equations and variables to calculate, possibly some empirical measurements by measuring the resistance of a trace, but Ohm’s Law is a law for a reason. If you do things right, you can make a PCB heat bed perfectly suited for the task. You can even design in safety features like overcurrent protection and fuses. It can’t be that hard. After all, your house is full of devices that are plugged into the wall.

I’m not remotely an experienced sports shooter, so I can have trouble tracking fast-moving subjects under the best of circumstances. Already finding tracking fast action closely challenging, I found tracking fast action closely based on a series of static images delayed by 1/10 second or more was quite a bit harder still. After a little practice, I got better at doing so, but I sometimes found myself resorting to tricks like keeping both eyes open while shooting, or shooting in short bursts and using the time between bursts to get the subject properly framed with full-time live view again.

The comments section of this article is disgusting. Most people throwing rocks at TJ have no idea what they’re talking about, or their concerns are obviously apparent to anyone reading TJ’s post.

“Twelve-gauge wire is good for 20 amps, 10-gauge wire is good for 30 amps, 8-gauge is good for 40 amps, and 6-gauge is good for 55 amps,” and “The circuit breaker or fuse is always sized to protect the conductor [wire].”

You’ll notice that I didn’t explain exactly how to correct this. I do this intentionally because I’m not going to do the work. This situation could be easily fixed by replacing the dimmer switch with a simple toggle switch, by installing a dimmer rated for a higher wattage, or by installing bulbs with a lower wattage. Any of those would be fine, but as the home inspector, I don’t design the repairs.

Heat pumps are good as pre-warmers but it’s hard to get really hot water from one without wasting a lot of electricity in the process as you exceed the “point of diminishing returns”. Natural Gas is still the cheapest most efficient way to heat water because it’s fairly easy to make a 95% or better efficiency burner. In Canada you’d likely have to go geothermal which in most cases is nothing but a heat pump hooked to an underground water loop